System of control for electric motors.



A. G. EASTWOOD. SYSTEM OF CONTROL FOR ELECTRIC MOTOR$. APPLICATION FILED 1330.3, 1908.

Patented Nov. 16,

2 SHEBTSSHEET l.

INVENTOR U Q ,QW. M h QM gnu W RM QM N N 7 RV v NE R an a mi x n H FI LH ATTORNEY A. G. EASTWOOD. SYSTEM OF CONTROL FOR ELECTRIC MOTORS. APPLICATION FILED DEG.3.1908.

ATTQRN EV R mm W 5 M w. w W m k i m n F m I! N WNNN W v fi wfi & D p h In Q QH Q 3% Q H 3%? \N H 5 @U \& n1, 3 N NQN W M N NJ? v 10 w W 3? L 0 B 4 n 9 w w ARTHUR EASTWOOD,

SYSTEM OF CONTROL F Specification of Letters Patent.

FICE.

OF CLEVELAND, 01-110.

0R ELECTRIC MOTORS.

rate'nted Nov. 15, 1909..

Application filed December 3, 1908. Serial No. 465,818.

To all whom it may concern:

Be it known that I, ARTHUR C; EAs'rwooo, a citizen of the United States, residing at Cleveland, in. the county of Cuyahoga and State of Ohio, have invented or discovered new and useful Improvements in Systems of Control for Electric Motors, of which the following is a specification.

My invention relates to an improved system of control for electric motors.

The object of my invention is to produce a system of control by means of which one or more motors maybe controlled both as to the direction of their rotation and their speed in either direction by means of a master controller, there'being but a single control conductor extending from the master controller to the speed and direction controlling devices of the motors to be controlled. Q

In carrying out my invention I make use of independently actuated switches for controlling the speed of the motor. In practice it has been found highly desirable, and in many cases essential, that the-operator be provided with controlling means of such nature that a reliable step by step control of motor speed be obtained. It has been further found in practice that independently actuated or unit switches form a preferable means for making and breaking the various circuits utilized in the speed control of motors, this being particularly true in the case of railway motors of considerable power and in cases where a number of motor driven cars are placed in a train and cohtrolled by a single master controller, usuall placed at the forward end of the leading car of the train.

Referring tothe accompanying drawings. Figure 1 shows a diagram of the electrical connections of my system of control appliedto rheostatic control of a single series wound motor, and Fig. 2 shows diagrammatically the same system of control ap liedv to the motors on several motor cars 0 a train, all of the motors being controlled from a master controller on the leading car of the train.

Referring to Fig. 1, S designates a double pole switch connected to the plus and minus sides of a power circuit.

A is the armature'of the motor to be controlled, and W the series field winding of the same.

18 and B are reversing switches of the electro-magnetically actuated type If the switch F is closed the armature of the motor will revolve in a forward direction; but when the switch B is closed the armature will revolve in a reversed direction.

R, R and R are sections of resistance governed by the electro-magnetically actuated switches S, S S and S 7 K is the master controller which is actuated by the operator to obtain the desired direction of rotation and speed of the motor. The master controller K is indicated as of the drum type having stationary contact fingers k, 10 k", and is, each arranged to cooperate with two systems of strips or contact segments carried by the drum of the controller at either side of its ofi-position. In Fig. 1 the drum of the controller is shown as developed in the ofi-position, in which posi' tion none of the contact fingers make contact with the segments in either system of strips.

1 is a single control conductor leading from the master controller K to the magnetically actuated motor controlling apparatus.

L is a differently wound relay which governs the connection of the control circuit to the power circuit.

4: and 5 are wires connecting fingers k and 7c of the master controller to the power circuit at a pointadjacent to the controller K, it being assumed that the power wires are available for: connection at this point as well as at the switch 8 which supplies current for the motor and for the control conductors 2' and 8. If now the drum of the master controller be revolved toward the left, contact strip is will come into contact 1 with the finger k and the lon .side of the contact strip of the row is wil bridge the lie circuits as follows: from the positive sid of the switch S, through the wire 2, the upper halfof the winding of the relay'L, the control conductor 1', the finger la, the strip is, through the connection to the strip is", thence to contact fin er k and the wire 4 to the negative side 0 the power circuit. This energizes the upper half of the winding of the/relay L and causes it to lift its plunger thereby closing the auxiliary switches Z 'and Z. The closure of the switch Z connects the control wire 2 to the wire 2, which in turn is connected to the positive side of contact fingers k? and 70 This will estabthe powercircuit at closure of the switch wire 3' nected to the negative cuit at the switch S.

it will be' observed that one side of the of the reversing switch i is conpositive side 01" the main switch 2, the switch P, the wire winding nected to the S through the wire 27, the auxiliary swit reversing switch B, and th the other end of this windin the wire 20, the current-hunting resistance the switch S and Z connects the control to the wire 3 which in turn is conor" the ower cirside ch 5 car'ied by 7', the wire 26, and the control conductor which in the first position or trolier as above noted, 18 connected to negativeside or tact finger is the line throu h the cona P the strip is, the contact ring-er 70 and the wire 1. lhe circuit through the e wire 2%, while g is connected to the master c econ the t-ive side of the iine through finger is, the strip 71:, the strip is, the contact finger 7s and the wire 5. The circuit through the winding of the switch S is then completed as follows: from the positive side of the line, through the w e 5, the contact finger if, the strip 1 0 the strip is, the contact finger is, the control conductor 1, the wire Z, the wire 26, the auxiliary switch the wire 25, the resistance r", the windin of the switch S, the 3-6, the control wire 3, the auxiliary switch 2 and the wire 3 to the negative side of the switch 5%. Switch S then closes. In nessing from the first position of the master controller to the g 0, the extended position correslcondin g lower portion of the contact strips k first opens circuit with the contact finger Z33, thereby cutting into I circuit the current the 7 onthe tee 20 winding of the reversing switch F is thus limiting resistance r. the cont 70 complete, causing the switch to close. 1 makes contact with the in; it switch F carries the auxiliary switch contact strip is opens the c tacts f, j, and f iitter the switch F has contact iinger 112 The cu closed, the closure of the switch j" compietes sistence r serves to limit the flow Ct the circuit of the winding of the reversing through a locai circuit which is established switch F as follows: from the positive side as follows: from the po'itive wire 5 to the ot the switch S, through the wire 2, the auxcontact finger k, thence to t 1 iliary switch Z the wire Qj'th wire 2?, is, the strip is, the contact iii auxiliary switch 5 the wire 2-1, the winding resistance to the negative of the coil of the switch F, the wire 20, the the contact strip 70 znalres co wire 29, the auxiliary switch 7, the wire 5, e cent-act finger Fa h the wire 3, the auxiliary switch Z and the control conductor 1 wire 3 to the negative side of the tive side of the "ie whiie i leer end of switch S. Through this circuit the reversing the winding of the relay L is sc connected switch is held closed through the suhto the positive through sequent operation the master controller upper half is winding,

in the forward direction. The switch f short, circuited carried by the reversing switch 3 opens iiows through? c lower he when the switch closes, thereby disconby way of the c i M necting the winding of he other reversing wire 8 to the ve side switch B from the wire 8, this connection The reia. L, the. efore,'re having previously existed through 1e wire closureot switch S" estub 22, the auxiliary switch ,4, end the wire cuit through motor 5* The reversing switch is therefore inoperpositive side of t ative as long as the reversing switch 3 is wire 13, the se closed. The auxiliary switch f carried by windin the reversing switch cioses a connection n the from the control conductor 1 to the winding Q blow-outof the'resistance switch 55 as follows: from the contacts 0 e switch 3 the wire Z, through the wire 26, the wire 31, armature A switch f the wire 25, through the :e- 1e blow-out i sistance 7* to the winding of the switc P and the wire I will he observed that the other end 0 i Th winding ot the switch S is connected thus completed w the wire 36 to the conductor 3, wh h rolling resistancesturn is connected to switch S through the ouxiliary switch Z is condition both i: l

the wire 3.

ends of winding D when the master con oosition. /Vhen, how r olier is advanced to tron COTEGSDOIKiEEifto control conductor 1 is nder connected to the negative the negative -si or troller is, in its ever, its

he motor shou rein :nun-

cioses. s iocai circuit switch S" follows: control wire w: the switch 8,

and the wire inc contact roe control wire 2. This circuit is maintained through subsequent operations of the master controller in the said direction from the offposition. The second auxiliary switch 8 carried by the switch S serves to connect one end of the winding of the switch S to the control conductor 1' through the wire 37 and the auxiliary switch 8 carried by the last resistance switch ,S*. In the position p of the master controller the control conductor is connected to the positive side of the line through the contact finger [0* as previously mentioned. It will be seen also that the upper end of the winding of the switch S is connected to the positive control wire 2 by the wire 38. No current, therefore, can flow through the winding of the switch S When, however, the master controller is moved to its next running position, indicated by the line 71 the control conductor will be again connected to the negative side of the line through the contact finger lo, the strip 7: and the lower portion of the strip is, the contact finger is", and the wire 4. The circuit will then be completed through the winding of the switch S and this switch will close, thus short circuiting the first section of the resistance R, thereby causing the motor to increase its speed. In a similar manner the switch S will close when the control conductor 1 is connected to the positive line through the finger k in the position 79 of the master controller. This will short circuit the section of the resistance R and give a still higher motor speed. In the final position of the master controller, indicated by pt, the control conductor will be again connected to the negative and the switch S will close, thus short circuitnig the remaining resistance Rf and giving full motor speed.

The switch S carries an auxiliary switch 8 which opens when the switch S closes. This serves to disconnect the control conductor 1 from the windings of all of the switches except that of the switch S which maintains its connection to the control conductor 1 through the wire 41 and the auxiliar'y switch 8' carried by the switch S It now the master controller K be returned to the oft-position, the control conductor 1 willbe disconnected from both sides of the line at the master controller and, therefore, the two halves of the winding ot'the relay L will beleft in series and across the supply mains, and, as already mentioned, these two halves of the winding oppose'each other so that no magnetization will result and the relay L will open, thus opening the auxiliary I switches Z and 1 This in turn disconnects the "control wires 2" and 3 from the source of current so that allof the switch windings of the controller are opened. Consequently, these switches open, thereby disconnecting the motor from the line. If now the master controller be operated in the reverse direction from the off-position to the position indicated by 7/ the control conductor '1 will first be connected to the positive side of the line through the contact finger is, the strip la, the strip lc, and the contact finger k. The lower half of the Winding of the relay L will then be energized, the switches Z and Z will close, thereby connecting the control wires 2 and 3' to the positive and negative sides of the switch S as before. The circuit will then be established as follows: from the control conductor 1, through the Wire 26, the resistance 1-, the wire 21, the winding of the reversing switch B, the wire 22, the auxiliary switch f and the wire 23 to the negative control wire 3. The reversing switch B will then close and after it has closed will establish a circuit for its winding as follows: from the positive control wire 2', through the wire 35, the auxiliary switch b, the wires 30 and 21, the winding of the switch B, the wire 22, the auxiliary switch 'f and the wire 23 to the negative control conductor 3. The reversing switch B in closing also opens the auxiliary switch 6 which in turn disconnects one end of the winding of the other reversing switch F from the positive control wire 2 to which it was previously connected through the wire 24:, the auxiliary switch 79 and the wire 27. The reversing switch F is, therefore, inoperative as long as the reversing switch B. is closed. The reversing switch B in closing also closes the auxiliary switch 5 which completes the circuit through the winding of 'the first resistance switch S as follows: from the positive connection 5 at the mastercontrol ler, through the contact finger k, the strip k, the strip is, the contact finger la, the control conductors 1 and 1, the wire 26, the wire 32, the auxiliary switch b the wires 34 and 25, and the resistance 'r, the winding of the switch S, and the wire 36 to the negative control wire\3'. The switch S then closes completing the circuit through the motor as follows: from the positive side of the switch S, through the wire 13, the resistance sections R R and R, the'switch S, the wire 14, the field winding W, the switch contacts B the wire 16, the armature A, the wire 15, the switch contacts B, and the wire 17 to thenegative side of the line at the switch S. It will be observed that current now flows through the arma ture in a direction the reverse of that previously described while the direction of current 'fiow through the fieldwinding is unchanged. The armature will, therefore ro- 'tate in a reversed direction. c

, When the master controller is moved to close in a manner identical with that which occurred when the'controller was given the position corresponding to p in the forward position. The switches S and S will likewise close in a similar manner as the controller is advanced to the full speed position. W hen the controller is again brought to the oil-position, the difierential windings of the relay L will oppose each other and the relay will drop its plunger, thus opening the switches Z and Z cutting oil the supply of current from all of the switch operating magnets in the controller thus causing these switches to open and disconnect the motor from the line.

It will be seen that my invention provides simple means for controlling both the direction of rotation and the speed of electric motors through the agency or" but a single control wire between the master controller and the controlling devices which control the connections to the motor and which are preferably placed adjacent to the motor to he controlled.

lt will, of course, evident to those skilled in the art that means other than the resistance sections ll, R and B may he made use of in controlling the speed or the motor. For instance, in the case of an alternating current motor the resistance sections might be replaced with sections in the winding of a transformer.

Referring now to Fig. 2, have therein illustrated my invention as applied to electrically operated trains equipped with number of motor driven cars indicated as C, (l and C ordinary railway cars D not equipped with motors interposed between the cars equipped with driving metors. The operating controller K is indicated as in connection with the leading motor car 0, the contacts of the controller heing shown outside of the outlines of the car for the sake of clearness. The control conductor 1 leading from the master controller K is shown as connected to the middle point of the winding of the relay L on the car "I; and also as connected through a contact shoe m with a stationary control conductor 9. The upper end of the relay winding is connected by means of a contact shoe 9?? to the main power conductor N which maybe a trolley wire or a stationary conducting rail, while-the other end of the winding of the relay L is indicated as connected to the truck of a car, which in turn, is connected to the rails Gr which form the return for the main power circuit. In Fig. 2 connections beyond the winding of the relay L have been omitted, it being understood that each of the motor driven cars would be equipped with controlling apparatus identical with that indicated diagrammatically in Fig. l, or with modifications of the same to meet the characteristics and number of the motors to be employed,

lt will'he observed that closure having one end of their or eal shown a stationary control conductor for connecting the master controller on the leading car of the train with the control appl ratus on the other cars in the train, t is being the arrangement disclosed in United States Patent No. 884,644, issued to me April 14, 1908, and heingthe preferable arrangement in a railway which cars of other lines are of necessity transported and to secure the best results are placed between the motor driven cars in making up trains. In a case ofrailways operating only their own cars the stationary control conductor 9 could, of course, be replaced by a single train conductor with ich all cars would be equipped together with flexible couplings at the ends of each car loy means of which all of the cars in a train could he so coupled that a continuous control conductor would extend through the length of the train.

claim-e Tu a control system, combination or a SCLJLGS of electrically-actuated speed-controlling switches, a control circuit, adjacent pairs of said switches having one end of their windings connected to opposite sides of the control circuit and the other end of their windings adapted to he connected to a common control conductor, and means for connecting said common control conductor to one and thento the other side of the control circuit. in order to cause the successive closure of the said speed-controlling switches.

2, In a control system, the combination of a control circuit, a plurality electricallyactuated speed-controlling stv-"cnes arranged to he closed in a predetermined order, succeeding switches in the order of their windings connected to opposite sides of the control circuit and the other ends adapted to he connected to a common control conductor, and means for alternately connectin said control conductor to-one side and-then to the other side of said control circuit.

In a control system, the combination a series electrically actuated switches the successive closure of which governs the speed or an electric motor, a master controller, a single conductor between master controller and the windings f said series of electrically actuated swi -ies, con tions being such that the step by step ac 11- tion of the said master-controller, causes successive energization of the windings said s ries of electrically switches.

i a control system, electric motor, an electrically governed r-eve sine s controlling the direction or re" motor, a plurality of independ switches for controlling e motor, master controller for action oi said reversing swi switches, said master controller and said reversing and speed controlling switches.

5. In a control system, a-reversing switch, a series of independently actuated speed controlling switches,'a master switch, a single conductor between said master switch and said reversing and speed controlling switches, and means at the master switch for producing successive reversals of the direction of currentflow through said control conductor for causing successive closure of said switches. t

6. In a control system, an electrically overned reversing switch and a plurality 0% independent electrically governed speed controlling switches, a master co'ntroller,-,a single control conductor between said master controller and said reversing and speed controlling switches, means at the master controller for successively reversing the direction of current flow through said control conductor when the master controller is actuated from the ofi position determining the action of said reversing switch and succeedmg reversals of the direction of current flow through said control conductor causing the successive actuation of said speed controlling switches.

7 In a control system, the combination of a power circuit, a control circuit derived from said power'circuit, an electrically governed reversing switch, independent electrically governed speed controlling switches arand a single conductor betweenranged to be governed by current supplied from said control circuit, a master controller, a single control conductor leading from said master switch and adapted to control the action of said reversing switch and the successive action of said speed controlling switches, means for connecting said control circuit to said power circuit while current is flowing through said control conductor in either direction, and means for disconnecting said control circuit from said power circult when current ceases toflow through said control conductor.

8. In a control system, a power circuit, a control circuit derived from said power circuit, a plurality of electrically governed motor control switches, the overning current for said switches being erived from said control circuit, a master switch, a single control conductor leading from said master switch, a diiferentially Wound. relay having contacts for connecting said control circuitto said power circuit, the ends of-the windin of said relay bein connected to the two si es of said power circuit and the middle point of said vwinding being connected to said sin lecontrol conductor.

Signe at Cleveland, Ohio,

this 1st day of .Dec., 1908.

ARTHUR C. EASTWOOD.

Witnesses H. L. STRATTON,

' l v H. M. DIEMER. 

